Rheostat



(No Model.) 2 Sheets-Sheet 2.

J. HARTMAN, Jr. A

RHBOSTAT.

. 170.371,937. Patented Oct. 25, 1887.

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UNITED STATES PATENT OFFICE.'

JOHN HARTMAN, JR., OF PHILADELPHIA, PENNSYLVANIA.

RH EOSTAT.

v SPECIFICATION forming part of Letters Patent No. 371,937,dated October 25, 1887.

Original application filed November l2, 1885, Serial No. 182,642. Divided and this application filed January 21, 1887. Serial No.

T all whom t may concern.

Be it known that I, JOHN HARTMAN, Jr., a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Rheoslats, of which the following is a specification.

This application is a division of an application for Letters Patent for an improvement in cars for electric railways, filed by me November 12,1885, Serial No. 182,612.

My invention consists in such a construc tion of the rheostat that by means of a lever upon its upper surface the same may be brought alternately into contact with the wires through which are passed the positive and negative currenisof electricity from adynamo, thus permitting of a change of polarity, as will be more fully understood from the following description.

In the accompanying drawings, which make a part of this specification, Figure l is a plan View of the rheostat. Fig. 2 is a side elevation with the inclosing-case Yin section. Fig. 3, Sheet No. 2, is a side elevation of the top of the rheostat with the studs cc and plate E removed. Fig. 4 is a like View. Fig. 5 is a like view taken in the direction of the arrow, Fig. 3. Figli is a view of the under surface of the lever D.

Like letters of reference in all the figures indicate the same parts.

O is the rheostat, upon the surface of which are the ends oi' the wiresbb', that extend downward through the body or case, their lower ends being connected to the positive and negative wires that lead up Vfrom aconductor which conveys currents generated from a dynamo. The positive current is then carried, by means of the wire Z12,connected at one end to the metallic plate E and at its other end to the coils (No model.)

of wire b3, through one of the intermediate metallic studs, c, which have connection with the coils b within the case. A similar connection with the wire b,connected to the wire b',carrics the negative .current to the plate E and to the coils b5. Upon the saine surface of the rheostat and extending through the case are the leading-in wires b 07.

D is the operating-lever, having pivotal inotion through its hub f/ by means of the pin g', passing through the stud or boss lz, central upon the face of the rheostat. This lever has a series of notched lugs, i, in a plate, It, (and insulated therefrom upon its under surface,) that are in range with the studs c, over which they pass and forni contact therewith for the passage of the current. This plate R is also provided with the lug fi', that forms contact with the wire bl. To the forward end of the lever, upon its under side, is also connected a plate, R', that has a notched 1ng,f2, that engages with the wire bi. This plate It'exteuds beyond the end of the lever in a parallel line and is caused to come into contact with the groove 7c in the plates E E during the partial rotating movements ot' the lever.

I claim as my invention, and desire to secure by Letters Patent- The rheostat C, having the wires b to bstuds c c', plates EE', having grooves k, in combination with the lever D, provided with plates R It', in which are the lugs or contact-pieces 11i i, for controlling and regulating the currents of electricity imparted to the motor, substantially in the manner herein shown and described.

J N O. HARTMAN, JR.

Vitnesses:

TrroMAs J. BEwLEY, CLIFFORD E. LARZELERE. 

